Subsystem 6a: Item Database + /item /recycle /craft /research calculators + refresh tool

[HandyS11]

Subsystem 6a — Item Database, core calculators & refresh tool

First slice of subsystem 6. Adds an offline, versioned Rust item dataset behind one lookup seam, four calculators exposed both in-game and as slash commands, and a maintainer generator tool so the bundled data can be refreshed instead of silently rotting.

What's new

RustPlusBot.Features.ItemData (new leaf project)

• Embedded, versioned item-data.json (1205 items) deserialized into a typed schema (ItemDataset / ItemRecord / …), with per-section provenance dates.
• IItemDatabase + singleton EmbeddedItemDatabase (FrozenDictionary, dup-id last-wins, SchemaVersion fail-fast).
• Pure ItemLookup → ItemMatch (Found / Ambiguous / NotFound): numeric-or-name resolution, exact-beats-substring, deterministic ranked "did you mean", exact-name collisions surface as Ambiguous.
• Supersedes 4c's name-only IItemNameResolver (StorageMonitors re-pointed onto the shared resolver; its private items.json deleted — one source of truth).

Calculators (in RustPlusBot.Features.Commands)

• In-game !item / !recycle / !craft / !research (terse, EN/FR, work while disconnected — static data).
• Slash /item / /recycle / /craft / /research (ephemeral embeds with a "data as of <date>" footer).
• Name-or-id argument; all four appear in /help under a new Item Database group.

Generator tool (tools/RustPlusBot.ItemData.Generator, not shipped in the bot)

• Transforms the rustplusplus static JSON into our schema, validates loudly, and refuses to overwrite a good bundle on shape drift. See its README.

Notes

• No new EF entities/migrations/events/options/background services — read-only static data.
• Deferred to a later slice: /decay, /upkeep, /durability, /smelting, /cctv; safe-zone/shredder recycle variants; a live-scrape source adapter; slash autocomplete.
• The calculator data (recycle/craft/research) is sourced from rustlabs and currently dates to 2024-09-07 — surfaced honestly via the per-result "data as of" footer; the generator tool refreshes it.

Verification

• Build 0/0 under -warnaserror; dotnet jb cleanupcode … --profile=ReformatAndReorder idempotent-clean.
• Full suite 586 tests / 16 assemblies green (baseline 551 + 35: ItemData 21, Generator 4, Commands +10). StorageMonitors unchanged (re-point is behavior-preserving).
• Built subagent-driven (per-task TDD + spec/quality reviews) with a final whole-branch review.

🤖 Generated with Claude Code